Fuel gauge still not workin, gonna drop tank maybe this weekend and check ground. It's pegging full when on so I'm assuming bad ground.

There are some other ground locations to check also on the gauge. I know, I spent a day once finding out. Sometimes there is a cluster of grounds behind the e-brake pedal. If not there, then for sure there will be a bunch of grounds on teh dipstick bracket, behind the distributor on the passenger's side of the engine block.

The tank ground is actually a steel tab which is spot-welded onto the top of the sender unit FWIW. The pump grounds to that on the inside of the tank.

There are some other ground locations to check also on the gauge. I know, I spent a day once finding out. Sometimes there is a cluster of grounds behind the e-brake pedal. If not there, then for sure there will be a bunch of grounds on teh dipstick bracket, behind the distributor on the passenger's side of the engine block.

The tank ground is actually a steel tab which is spot-welded onto the top of the sender unit FWIW. The pump grounds to that on the inside of the tank.

Hello, I am on my second 90 YJ. You have done very well so far! Before dropping the tank, you might trace out the wiring in the harness at the left rear corner of the Jeep. You can probe the wires and figure out which one is power and which one is the ground signal. Read the relative ohm value (if the sender works) 90-0 depending on actual fuel level. This may help prove if your sender is bad or not, before you drop the tank.

If you are planning to drop the tank, I suggest you have about 3' of 1/4" & 3' of 5/16" fuel line to replace what's there. New clamps on hand would be a good idea too. A piece of duct tape to hold the new lines down in the valley of the top of the tank works well. This will avoid pinching the new lines when you put the tank back up. ( They do pinch easy too, since there is next to no room for margin of error in there.) Good luck.

ground is black....look up in on the side by the ebrake, if u see a black wire it will bethe ground, if its attached try cleaning it and doing it back up, mine was just hanging there from the PO and some wiring he had done on the stereo.....

stupid thing didnt work for 4 years and 10 seconds later works perfect,.... AHHhhhHHhh

Your best bet is to get a copy of the Hayne's manual and/or a Chilton's. Both should be in stock at larger auto parts stores.

Going from my memory, the tan wire at the dash cluster (and also the pump harness) is the one for the sender and gauge. You want to check the tan one with an ohm meter, the sender should vary from zero to 90 ohms.

Black is ground. Black with a small orange stripe is "hot" for the pump.

Best of all is to go on ebay and find a copy of the factory (dealership) service manual (FSM). There are people who still publish it but it costs like $120.

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Last edited by pete1991YJ; 02-22-2013 at 11:10 AM..
Reason: explanation

That diagram won't apply here. The OP has a carbed six with a mechanical fuel pump. No pump in tank.

There is a molex connector inside the left rear corner of the tub above the plastic mud shield ( behind the left tail lamp). From my memory, you can look at the wire loom and see the wires that disappear to the top of the tank. 3 of them. A ground, a positive signal wire, and the signal back to the gauge, which I think was tan. Its easy to confirm the signal color wire if you take out the gauge cluster and look at the connector and trace the copper ribbon to he fuel gauge pin out. You can ground the signal wire to simulate a full reading to verify the gauge works. Ohm out the sender to see if you have a resistance reading between 0-90 ohms. Sorry to leave you here, but there are a few write ups on this forum about this

That diagram won't apply here. The OP has a carbed six with a mechanical fuel pump. No pump in tank.

There is a molex connector inside the left rear corner of the tub above the plastic mud shield ( behind the left tail lamp). From my memory, you can look at the wire loom and see the wires that disappear to the top of the tank. 3 of them. A ground, a positive signal wire, and the signal back to the gauge, which I think was tan. Its easy to confirm the signal color wire if you take out the gauge cluster and look at the connector and trace the copper ribbon to he fuel gauge pin out. You can ground the signal wire to simulate a full reading to verify the gauge works. Ohm out the sender to see if you have a resistance reading between 0-90 ohms. Sorry to leave you here, but there are a few write ups on this forum about this

It is indeed tan and goes to pin 8 (IIRC) similar to the diagram. Same deal on my injected model. Grounds are black (and most likely corroded all to heck and gone).

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Picked up one of these little hitches today at autozone. I was gonna bolt/weld it to my rear bumper. Just to pull a small 4x8 trailer to haul trash to dump weekly. I'm talkin less than 500lb load. "Average 150lb a week, 4 kids and one of them in diapers, man we make a lot of garbage" anyhow can I get opinions on these before I weld it up? In case I need to take it back instead.

How can I tell what tranny I have? Cold mornings it feels like I'm shifting a stick in mud. The oil is thick. I wanna service it. I think it's a ax-15 but wanna make sure.

The 6-cylinders all had the AX-15 far as I know. Earlier models 87-89 *might* have had the piece-of-crap Renault BA-10/5. That one is easy to spot because its case splits longitudinally.

The 4-cylinders all had the AX-5 far as I know.

Both trannies are very well supported with all the guts and rebuild kits available at Quadratec. The recommended oil is 10-W30 motor oil. Yep you read that right. Takes about 2 quarts.
The easy way to fill it it thru the shift tower ntil it runs out the side fill plug. Hope that clarifies!

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